EDC LAB (180) II-I

LABORATORY MANUAL

ELECTRONIC DEVICES & CIRCUITS LAB

II B. Tech I-SEM

DEPARTMENT OF

ELECTRONICS & COMMUNICATION ENGINEERING

Malla Reddy College Of Engineering and Technology

Maisammaguda, Dhulapally(Post),via Hakimpet,Secunderabad-500014

PREREQUISITES FOR ELECTRONICS LABS-A BASIC UNDERSTANDING

1. BASIC ELECTRONIC COMPONENTS 1

1.1 RESISTOR 1

1.2 COLOUR CODING OF RESISTOR 1

1.3 TYPES OF RESISTORS 3

1.4 CAPACITOR 5

1 .5 COLOUR CODING OF CAPACITORS 6

1.6 COLOUR CODING OF INDUCTORS 10

2. CIRCUIT SYMBOLS 11

3. STUDY OF CRO 19

4. STUDY OF FUNCTION GENERATOR 25

5. STUDY OF REGULATED POWER SUPPLY 28

6. TYPES OF CIRCUIT BOARD 29

LIST OF EXPERIMENTS

1. P-N JUNCTION DIODE CHARACTERISTICS 31

2. ZENER DIODE CHARACTERISTICS AND ZENER DIODE AS A VOLTAGE REGULATOR 35

3. TRANSITOR COMMON -BASE CONFIGURATION CHARACTERISTICS 40

4. TRANSITOR COMMON - EMITTER CONFIGURATION CHARACTERISTICS 45

5. HALF -WAVE RECTIFIER WITH AND WITHOUT FILTER 50

6. FULL - WAVE RECTIFIER WITH AND WITHOUT FILTER 55

7. FET CHARACTERISTICS 59

8. h-PARAMETERS OF CE CONFIGURATION 63

9. FREQUENCY RESPONSE OF CE AMPLIFIER 69

10. FREQUENCY RESPONSE OF CC AMPLIFIER 75

11. FREQUENCY RESPONSE OF COMMON SOURCE FET AMPLIFIER 80

12. SILICON-CONTROLLED RECTIFIER (SCR) CHARACTERISTICS 84

13. UJT CHARACTERISTICS 87

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1. BASIC ELECTRONIC COMPONENTS

1.1. RESISTOR

A Resistor is a passive two-terminal electrical component that implements electrical

resistance as a circuit element. The current through a resistor is in direct proportion to the

voltage across the resistor's terminals. This relationship is represented by Ohm's law:

Where I is the current through the conductor in units of amperes, V is the potential

difference measured across the conductor in units of volts, and R is the resistance of the

conductor in units of ohms.

The ratio of the voltage applied across a resistor's terminals to the intensity of current in

the circuit is called its resistance, and this can be assumed to be a constant (independent

of the voltage) for ordinary resistors working within their ratings.

1.2. COLOUR CODING OF RESISTOR

Colour Codes are used to identify the value of resistor. The numbers to the Colour are

identified in the following sequence which is remembered as BBROY GREAT

BRITAN VERY GOOD WIFE (BBROYGBVGW) and their assignment is listed in

following table.

Black Brown Red Orange Yellow Green Blue Violet Grey White

0 1 2 3 4 5 6 7 8 9

Table 1: Colour codes of resistor

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Figure 1: Procedure to find the value of Resistor using Colour codes

Resistor Color Codes: Resistors are devices that limit current flow and provide a voltage

drop in electrical circuits. Because carbon resistors are physically small, they are color-

coded to identify their resistance value in Ohms. The use of color bands on the body of a

resistor is the most common system for indicating the value of a resistor. Color-coding is

standardized by the Electronic Industries Association (EIA).

Use the Resistor Color Code Chart (above) to understand how to use the color code

system. When looking at the chart, note the illustration of three round resistors with

numerous color code bands. The first resistor in the chart (with 4 bands) tells you the

minimum information you can learn from a resistor. The next (a 5-band code) provides a

little more information about the resistor. The third resistor (a 6-band) provides even

more information. Each color band is associated with a numerical value.

How to read a typical 4-band, 5-band and 6-band resistor: 4-Band: Reading the

resistor from left to right, the first two color bands represent significant digits , the third

band represents the decimal multiplier, and the fourth band represents the tolerance. 5-

Band: The first three color bands represent significant digits, the fourth band represents

the decimal multiplier, and the fifth band represents the tolerance. 6-Band: The first

three color bands represent significant digits, the fourth band represents the decimal

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multiplier, the fifth band represents the tolerance, and the sixth band represents the

temperature coefficient.

Definitions of color bands: The color of the multiplier band represents multiples of 10,

or the placement of the decimal point. For example: ORANGE (3) represents 10 to the

third power or 1,000. The tolerance indicates, in a percentage, how much a resistor can

vary above or below its value. A gold band stands for +/- 5%, a silver band stands for +/-

10%, and if there is no fourth band it is assumed to be +/- 20%. For example: A 100-Ohm

5% resistor can vary from 95 to 105 Ohms and still be considered within the

manufactured tolerance. The temperature coefficient band specifies the maximum change

in resistance with change in temperature, measured in parts per million per degree

Centigrade (ppm/C).

Example (from chart): Lets look at the first resistor on the chart. In this case, the first

color band is BROWN. Following the line down the chart you can see that BROWN

represents the number 1. This becomes our first significant digit. Next, look at the second

band and you will see it is BLACK. Once again, follow the line down to the bar scale; it

holds a value of 0, our second significant digit. Next, look at the third band, the

multiplier, and you will see it is ORANGE. Once again, follow the line down to the bar

scale; it holds a value of 3. This represents 3 multiples of 10 or 1000. With this

information, the resistance is determined by taking the first two digits, 1 and 0 (10) and

multiplying by 1,000. Example: 10 X 1000 = 10,000 or 10,000 Ohms. Using the chart,

the fourth band (GOLD), indicates that this resistor has a tolerance of +/- 5%. Thus, the

permissible range is: 10,000 X .05 = +/- 500 Ohms, or 9,500 to 10,500 Ohms.

1.3. TYPES OF RESISTORS

1. Carbon Resistors

2. Wire wound Resistors

Carbon Resistors

There are many types of resistors, both fixed and variable. The most common type for

electronics use is the carbon resistor. They are made in different physical sizes with

power dissipation limits commonly from 1 watt down to 1/8 watt. The resistance value

and tolerance can be determined from the standard resistor color code.

A variation on the color code is used for precision resistors which may have five colored

bands. In that case the first three bands indicate the first three digits of the resistance

value and the fourth band indicates the number of zeros. In the five band code the fifth

band is gold for 1% resistors and silver for 2%.

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Figure 2: Images of Carbon Resistors

Wire Wound Resistors

Wire wound resistors are commonly made by winding a metal wire, usually nichrome,

around a ceramic, plastic, or fiberglass core. The ends of the wire are soldered or welded

to two caps or rings, attached to the ends of the core. The assembly is protected with a

layer of paint, molded plastic, or an enamel coating